The high transmissibility, mortality, and morbidity rate of the SARS-CoV-2 Delta (B.1.617.2) variant have raised concerns regarding vaccine effectiveness (VE). To address this issue, all publications relevant to the effectiveness of vaccines against the Delta variant were searched in the Web of Science, Scopus, EMBASE, and Medline (via PubMed) databases up to 15 October 2021. A total of 15 studies (36 datasets) were included in the meta-analysis. After the first dose, the VE against the Delta variant for each vaccine was 0.567 (95% CI 0.520–0.613) for Pfizer-BioNTech, 0.72 (95% CI 0.589–0.822) for Moderna, 0.44 (95% CI 0.301–0.588) for AstraZeneca, and 0.138 (95% CI 0.076–0.237) for CoronaVac. Meta-analysis of 2,375,957 vaccinated cases showed that the Pfizer-BioNTech vaccine had the highest VE against the infection after the second dose, at 0.837 (95% CI 0.672–0.928), and third dose, at 0.972 (95% CI 0.96–0.978), as well as the highest VE for the prevention of severe infection or death, at 0.985 (95% CI 0.95–0.99), amongst all COVID-19 vaccines. The short-term effectiveness of vaccines, especially mRNA-based vaccines, for the prevention of the Delta variant infection, hospitalization, severe infection, and death is supported by this study. Limitations include a lack of long-term efficacy data, and under-reporting of COVID-19 infection cases in observational studies, which has the potential to falsely skew VE rates. Overall, this study supports the decisions by public health decision makers to promote the population vaccination rate to control the Delta variant infection and the emergence of further variants.

Objective: Absence of nocturnal blood pressure (BP) dipping is associated with poor health outcomes, including increased mortality. Non-dipper BP seems to be a predictor of cardiovascular damage in hypertensive patients. The aim of this study was to investigate the association of the mean platelet volume (MPV) and red cell distribution width (RDW) with nocturnal dipping/non dipping status in newly diagnosed and untreated prehypertensive non-smokers, using ambulatory BP monitoring. Results: Twenty-eight patients (15 males) in the dipper group and 24 patients (11 males) in the non-dipper group were evaluated in this study. The age of patients was 41.64 ± 15.01 and 37.96 ± 15.08 years in the dipper and non-dipper groups, respectively. The rate of nocturnal systolic BP drop in the dipper and non-dipper groups was 13.79 ± 3.35% (10.20–22.10) and 5.96 ± 2.87% (1.10–9.30) (P < 0.001), respectively. Also, the mean rate of nocturnal diastolic BP drop in the dipper and non-dipper groups was 17.02 ± 5.09% (10.30–26.90) and 6.19 ± 2.75% (1.20–9.70) (P < 0.001), respectively. RDW and MPV were significantly higher in non-dipper patients than dipper patients (P = 0.001 and P = 0.012, respectively). Bivariate analysis revealed that MPV was inversely correlated with the nocturnal systolic BP drop (P = 0.005, r = − 0.385). Furthermore, RDW was inversely correlated with systolic BP drop (P = 0.019, r = − 0.324).

Background: SARS-CoV-2 induced coagulopathy can lead to thrombotic complications such as stroke. Cerebral venous sinus thrombosis (CVST) is a less common type of stroke which might be triggered by COVID-19. We present a series of CVST cases with SARS-CoV-2 infection. Methods: In a multinational retrospective study, we collected all cases of CVST in SARS-CoV-2 infected patients admitted to nine tertiary stroke centers from the beginning of the pandemic to June 30 ^th , 2020. We compared the demographics, clinical and radiological characteristics, risk factors, and outcome of these patients with a control group of non-SARS-CoV-2 infected CVST patients in the same seasonal period of the years 2012-2016 from the country where the majority of cases were recruited. Results: A total of 13 patients fulfilled the inclusion criteria (62% women, mean age 50.9± 11.2 years). Six patients were discharged with good outcomes (mRS≤2) and three patients died in hospital. Compared to the control group, the SARS-CoV-2 infected patients were significantly older (50.9 versus 36.7 years, p <0.001), had a lower rate of identified CVST risk factors (23.1% versus 84.2%, p <0.001), had more frequent cortical vein involvement (38.5% versus 10.5%, p : 0.025), and a non-significant higher rate of in-hospital mortality (23.1% versus 5.3%, p : 0.073). Conclusion: CVST should be considered as potential comorbidity in SARS-CoV-2 infected patients presenting with neurological symptoms. Our data suggest that compared to non-SARS-CoV-2 infected patients, CVST occurs in older patients, with lower rates of known CVST risk factors and might lead to a poorer outcome in the SARS-CoV-2 infected group.